4.19-stable review patch. If anyone has any objections, please let me know.
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From: Kan Liang kan.liang@linux.intel.com
commit 8041ffd36f42d8521d66dd1e236feb58cecd68bc upstream.
The client IMC bandwidth events currently return very large values:
$ perf stat -e uncore_imc/data_reads/ -e uncore_imc/data_writes/ -I 10000 -a
10.000117222 34,788.76 MiB uncore_imc/data_reads/ 10.000117222 8.26 MiB uncore_imc/data_writes/ 20.000374584 34,842.89 MiB uncore_imc/data_reads/ 20.000374584 10.45 MiB uncore_imc/data_writes/ 30.000633299 37,965.29 MiB uncore_imc/data_reads/ 30.000633299 323.62 MiB uncore_imc/data_writes/ 40.000891548 41,012.88 MiB uncore_imc/data_reads/ 40.000891548 6.98 MiB uncore_imc/data_writes/ 50.001142480 1,125,899,906,621,494.75 MiB uncore_imc/data_reads/ 50.001142480 6.97 MiB uncore_imc/data_writes/
The client IMC events are freerunning counters. They still use the old event encoding format (0x1 for data_read and 0x2 for data write). The counter bit width is calculated by common code, which assume that the standard encoding format is used for the freerunning counters. Error bit width information is calculated.
The patch intends to convert the old client IMC event encoding to the standard encoding format.
Current common code uses event->attr.config which directly copy from user space. We should not implicitly modify it for a converted event. The event->hw.config is used to replace the event->attr.config in common code.
For client IMC events, the event->attr.config is used to calculate a converted event with standard encoding format in the custom event_init(). The converted event is stored in event->hw.config. For other events of freerunning counters, they already use the standard encoding format. The same value as event->attr.config is assigned to event->hw.config in common event_init().
Reported-by: Jin Yao yao.jin@linux.intel.com Tested-by: Jin Yao yao.jin@linux.intel.com Signed-off-by: Kan Liang kan.liang@linux.intel.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Cc: Alexander Shishkin alexander.shishkin@linux.intel.com Cc: Andy Lutomirski luto@kernel.org Cc: Arnaldo Carvalho de Melo acme@redhat.com Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: H. Peter Anvin hpa@zytor.com Cc: Jiri Olsa jolsa@redhat.com Cc: Linus Torvalds torvalds@linux-foundation.org Cc: Peter Zijlstra peterz@infradead.org Cc: Rik van Riel riel@surriel.com Cc: Stephane Eranian eranian@google.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Vince Weaver vincent.weaver@maine.edu Cc: stable@kernel.org # v4.18+ Fixes: 9aae1780e7e8 ("perf/x86/intel/uncore: Clean up client IMC uncore") Link: https://lkml.kernel.org/r/20190227165729.1861-1-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/events/intel/uncore.c | 1 + arch/x86/events/intel/uncore.h | 12 ++++++------ arch/x86/events/intel/uncore_snb.c | 4 +++- 3 files changed, 10 insertions(+), 7 deletions(-)
--- a/arch/x86/events/intel/uncore.c +++ b/arch/x86/events/intel/uncore.c @@ -740,6 +740,7 @@ static int uncore_pmu_event_init(struct /* fixed counters have event field hardcoded to zero */ hwc->config = 0ULL; } else if (is_freerunning_event(event)) { + hwc->config = event->attr.config; if (!check_valid_freerunning_event(box, event)) return -EINVAL; event->hw.idx = UNCORE_PMC_IDX_FREERUNNING; --- a/arch/x86/events/intel/uncore.h +++ b/arch/x86/events/intel/uncore.h @@ -285,8 +285,8 @@ static inline unsigned int uncore_freerunning_counter(struct intel_uncore_box *box, struct perf_event *event) { - unsigned int type = uncore_freerunning_type(event->attr.config); - unsigned int idx = uncore_freerunning_idx(event->attr.config); + unsigned int type = uncore_freerunning_type(event->hw.config); + unsigned int idx = uncore_freerunning_idx(event->hw.config); struct intel_uncore_pmu *pmu = box->pmu;
return pmu->type->freerunning[type].counter_base + @@ -360,7 +360,7 @@ static inline unsigned int uncore_freerunning_bits(struct intel_uncore_box *box, struct perf_event *event) { - unsigned int type = uncore_freerunning_type(event->attr.config); + unsigned int type = uncore_freerunning_type(event->hw.config);
return box->pmu->type->freerunning[type].bits; } @@ -368,7 +368,7 @@ unsigned int uncore_freerunning_bits(str static inline int uncore_num_freerunning(struct intel_uncore_box *box, struct perf_event *event) { - unsigned int type = uncore_freerunning_type(event->attr.config); + unsigned int type = uncore_freerunning_type(event->hw.config);
return box->pmu->type->freerunning[type].num_counters; } @@ -382,8 +382,8 @@ static inline int uncore_num_freerunning static inline bool check_valid_freerunning_event(struct intel_uncore_box *box, struct perf_event *event) { - unsigned int type = uncore_freerunning_type(event->attr.config); - unsigned int idx = uncore_freerunning_idx(event->attr.config); + unsigned int type = uncore_freerunning_type(event->hw.config); + unsigned int idx = uncore_freerunning_idx(event->hw.config);
return (type < uncore_num_freerunning_types(box, event)) && (idx < uncore_num_freerunning(box, event)); --- a/arch/x86/events/intel/uncore_snb.c +++ b/arch/x86/events/intel/uncore_snb.c @@ -444,9 +444,11 @@ static int snb_uncore_imc_event_init(str
/* must be done before validate_group */ event->hw.event_base = base; - event->hw.config = cfg; event->hw.idx = idx;
+ /* Convert to standard encoding format for freerunning counters */ + event->hw.config = ((cfg - 1) << 8) | 0x10ff; + /* no group validation needed, we have free running counters */
return 0;